Seat-mounted airbag device

ABSTRACT

A seat-mounted airbag device includes an inflator, an airbag body, and a guide member. The airbag body includes a front-rear chamber and a tip chamber. The front-rear chamber is deployed forward of a seat through a clearance between a window and a head of an occupant from a side portion of a headrest on a window side by gas ejected from the inflator and disposed between the window and the head of the occupant. The tip chamber is deployed inward in a seat width direction from an end portion of the front-rear chamber on a seat front side and disposed forward of a face of the occupant on the seat front side. The guide member protrudes from the side portion prior to deployment of the airbag body and is interposed between the airbag body and the head of the occupant.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Japanese Patent Application No.2021-096914 filed on Jun. 9, 2021, incorporated herein by reference inits entirety.

BACKGROUND 1. Technical Field

The present disclosure relates to a seat-mounted airbag device.

2. Description of Related Art

A side airbag device has been known in which the side airbag deviceincludes an airbag body portion that is deployed forward from one sideof a seat back and that is disposed on the upper body (including thehead) side of an occupant and an airbag protruding portion that isdeployed inward in a seat width direction from the airbag body portionand that is disposed forward of the face of the occupant in the event ofa frontal collision of a vehicle (see, for example, Japanese UnexaminedPatent Application Publication No. 2006-008105 (JP 2006-008105 A)).

SUMMARY

However, when the airbag device is mounted on the side of the seat backfacing a window side and the head of the occupant is closer to thewindow side during a frontal collision of the vehicle, a clearancebetween the window and the head of the occupant becomes narrow and itbecomes difficult for an airbag to be deployed, which may cause delay indeployment of the airbag. Especially in a case of an airbag housed to befolded in a bellows shape of which the deployment speed is high, theairbag may get caught on the head of an occupant during deployment ofthe airbag. As described above, there is room for improvement in theairbag device in which the airbag is deployed through the clearancebetween the window and the head of the occupant.

Therefore, the present disclosure provides a seat-mounted airbag devicein which the airbag body is smoothly deployed even when the clearancebetween the window and the head of the occupant is narrow.

The seat-mounted airbag device according to an aspect of the presentdisclosure includes an inflator that is operated when a vehiclecollision is detected or predicted and ejects gas, an airbag body thatincludes a front-rear chamber that is deployed forward of a seat througha clearance between a window and a head of an occupant from a sideportion of a headrest on a window side by the gas ejected from theinflator and disposed between the window and the head of the occupantand a tip chamber that is deployed inward in a seat width direction froman end portion of the front-rear chamber on a seat front side anddisposed forward of a face of the occupant on the seat front side, and aguide member that protrudes from the side portion prior to deployment ofthe airbag body and is interposed between the airbag body and the headof the occupant.

According to the aspect of the present disclosure, when the airbag bodyis deployed forward of the seat through the clearance between the windowand the head of the occupant from the side portion of the headrest onthe window side by the gas ejected from the inflator, the guide memberinterposed between the airbag body and the head of the occupantprotrudes from the side portion prior to the deployment of the airbagbody. Therefore, even when the airbag body is deployed from the sideportion of the headrest on the window side, there is no possibility thatthe airbag body will get caught on the head of the occupant. Therefore,even when the head of the occupant is closer to the window side and theclearance between the window and head of the occupant is narrow, theairbag body is smoothly deployed.

Further, in the seat-mounted airbag device according to the aspect, theguide member may be composed of a cloth.

According to the aspect, the guide member may be composed of the cloth.Therefore, even when the guide member hits the head of the occupant, thehead of the occupant is less likely to be hurt than when the guidemember is composed of, for example, a plastic material.

Further, in the seat-mounted airbag device according to the aspect, theguide member may be composed of a front wall of the side portion.

According to the aspect, the guide member may composed of the front wallof the side portion. Therefore, the manufacturing cost of the headrestis reduced as compared with a case where the guide member is providedseparately from the side portion.

Further, in the seat-mounted airbag device according to the aspect, theguide member may be composed of a front wall of the side portion and acloth provided in the front wall.

According to the aspect, the guide member may composed of the front wallof the side portion and the cloth provided in the front wall. Therefore,the manufacturing cost of the headrest is reduced as compared with acase where the guide member is composed of only the cloth.

As described above, according to the present disclosure, even when theclearance between the window and the head of the occupant is narrow, theairbag body can be smoothly deployed.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, advantages, and technical and industrial significance ofexemplary embodiments of the disclosure will be described below withreference to the accompanying drawings, in which like signs denote likeelements, and wherein:

FIG. 1 is a side view showing a seat-mounted airbag device according tothe present embodiment in a deployed state;

FIG. 2 is a plan view showing the seat-mounted airbag device accordingto the present embodiment in a deployed state;

FIG. 3 is an enlarged plan view showing a state in which a seat-mountedairbag device according to a first embodiment before being deployed ispartially broken;

FIG. 4 is an enlarged plan view showing a state in which theseat-mounted airbag device according to the first embodiment in adeploying state is partially broken;

FIG. 5 is a developed view showing an enlarged state of an airbag body,which is in an unfolded state, in the seat-mounted airbag deviceaccording to the first embodiment;

FIG. 6 is an enlarged plan view showing a state in which a seat-mountedairbag device according to a second embodiment in a deploying state ispartially broken;

FIG. 7 is an enlarged plan view showing a state in which a seat-mountedairbag device according to a third embodiment before being deployed ispartially broken; and

FIG. 8 is an enlarged plan view showing a state in which theseat-mounted airbag device according to the third embodiment in adeploying state is partially broken.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments according to the present disclosure will bedescribed in detail with reference to the drawings. For convenience ofdescription, the arrow UP, the arrow FR, and the arrow RH appropriatelyshown in the figures indicate the upward direction of a seat, theforward direction of the seat, and the right direction of the seat,respectively. Thus, when terms indicating directions, i.e., upward anddownward, forward and rearward, and right and left are used in thefollowing description without any specification, these mean upward anddownward of the vehicle seat, forward and rearward of the vehicle seat,and right and left of the vehicle seat. Further, the right-leftdirection is synonymous with a seat width direction.

Further, a seat-mounted airbag device (hereinafter, simply referred toas an “airbag device”) 30 according to the present embodiment isprovided inside a case portion 20 (to be described below) constituting aheadrest 16 of a vehicle seat 10 as a rear seat of a vehicle. Therefore,although the vehicle seat 10 according to the present embodiment isdescribed as a rear seat, the airbag device 30 may be provided in afront seat.

Further, as will be described below, the airbag device 30 is deployedforward through the clearance between the side window 18 as a window anda head Ph of an occupant P (along a side window 18). Therefore, thisairbag device 30 is applied to a vehicle that does not include a curtainairbag device, and a front-rear chamber 34 to be described belowfunctions as a curtain airbag.

Further, the “window” in the present embodiment includes a state inwhich the side window 18 is open as well as a state in which the sidewindow 18 is closed. Further, the “occupant P” in the present embodimentis, for example, an occupant corresponding to an AM 50 dummy doll.

First Embodiment

First, the airbag device 30 according to a first embodiment will bedescribed. As shown in FIGS. 1 and 2 , the vehicle seat 10 includes aseat cushion 12 on which the occupant P sits (supports the buttocks andthighs of the occupant P), a seat back 14 that supports the back of theoccupant P, and the headrest 16 that supports the head Ph of theoccupant P.

The headrest 16 includes a body portion 16A having a block shape that isprovided at the center of the upper end portion of the seat back 14 inthe seat width direction such that the body portion 16A can move up anddown. Specifically, a pair of right and left stays having a columnarshape (not shown) is provided at the center of the lower surface of thebody portion 16A in the seat width direction.

Each stay is inserted in each of a pair of right and left headrestsupports 26 having a substantially cylindrical shape that is provided atthe center of the upper end portion of the seat back 14 in the seatwidth direction (see FIGS. 3 and 4 ) so as to move up and down and beable to be fixed at a plurality of predetermined positions. Further, theheadrest 16 includes the case portion 20 continuously provided from therear of the body portion 16A to both the right and left sides.

That is, the case portion 20 is formed in a substantially “U” shape withthe front side open in a plan view. The body portion 16A is disposed onthe inner side of the case portion 20 with almost no clearance. In thecase portion 20, the front end surfaces (outer surface of a front wall20F) of the right and left side portions 24 extending in a front-reardirection are substantially flush with the front surface of the bodyportion 16A (see FIGS. 2 and 3 ).

Further, right and left outer walls 20A (side portions 24) and a rearwall 20B of the case portion 20 are composed of a resin cover member 22having a substantially “U” shape in a plan view. The upper wall (notshown), the lower wall (not shown), a front wall 20F, and an innerperipheral wall 20C facing the body portion 16A in the case portion 20are composed of urethane foam 23, and the outer surface of the covermember 22 and the urethane foam 23 is integrally covered with a skinmaterial 21.

A predetermined space portion S (including a housing portion S1 and alocating portion S2 to be described later) is provided inside the caseportion 20. An airbag body 32 of the airbag device 30 is housed in thehousing portion S1 provided in a side portion 24R of the case portion 20on the side window 18 side (right side in the figure).

As shown in FIGS. 1 and 2 , the airbag device 30 includes the airbagbody 32 that is deployed forward from the rear side of the head Ph ofthe occupant P (specifically right rear side) seated on the vehicle seat10 when gas is ejected from an inflator 28 (see FIGS. 3 and 4 ) to bedescribed below.

The airbag body 32 includes the front-rear chamber 34 that is disposedbetween the side window 18 and the head Ph of the occupant P and a tipchamber 36 that is deployed inward in the seat width direction from thefront end portion of the front-rear chamber 34 and is disposed forwardof the face of the occupant P. Then, the airbag body 32 includes atether 38 having a string shape that connects a predetermined positionat the upper end portion of the front-rear chamber 34 and apredetermined position at the upper end of the tip chamber 36.

That is, the airbag body 32 is bent in a substantially “V” shape in aplan view to restrain at least a part of the head Ph and the chest ofthe occupant P. The tether 38 may be provided so as to connect at leastthe upper end portion of the front-rear chamber 34 and the upper endportion of the tip chamber 36, and provided, for example, so as tofurther connect a predetermined position at the lower end portion of thefront-rear chamber 34 and a predetermined position at the lower endportion of the tip chamber 36.

As shown in FIG. 3 , the inflator 28 is disposed in the locating portionS2 that is the rear side of the space portion S provided in the caseportion 20. The inflator 28 has a substantially cylindrical shape, andthe outer peripheral portion thereof is supported by a reaction forceplate (not shown) having a housing shape via a retainer (not shown) suchthat the axial center portion thereof is disposed along the seat widthdirection.

The reaction force plate is fixed to, for example, a seat back frame(not shown) via a bracket (not shown), and is configured to be able toreceive reaction force transmitted from the airbag body 32 deployedforward via the inflator 28. The reaction force plate and the retainerare also located in the locating portion S2.

The inflator 28 is electrically connected to an airbag electroniccontrol unit (ECU) (not shown) provided in the vehicle, and a detectiondevice (not shown) such as an acceleration sensor provided in thevehicle and the airbag ECU are electrically connected. Therefore, when acollision of the vehicle is detected by the detection device, theinflator 28 is operated via the airbag ECU to instantly eject the gas.

The inflator 28 may not be configured to be operated when a collision ofthe vehicle is detected, but may be configured to be operated when acollision of the vehicle is predicted by a collision prediction sensoror the like (not shown). Then, a connecting portion 31 (see also FIG. 5) of the airbag body 32 is fitted and connected to the ejection port ofthe inflator 28.

The airbag body 32 is housed in the housing portion S1 provided in theside portion 24R in a state in which the airbag body 32 is folded in abellows shape (a plurality of folds that cross each other at apredetermined length) in a plan view. Therefore, as shown in FIG. 4 ,the airbag body 32 is deployed forward through the clearance between theside window 18 and the head Ph of the occupant P from the side portion24R (along the side window 18) while the airbag body 32 having a bellowsshape is unwound by the gas ejected from the inflator 28.

Further, the front wall 20F constituting the front end surface of theside portion 24R is broken, for example, linearly along the up-downdirection when the airbag body 32 is deployed. In some embodiments, aportion to be broken may be a seat width direction outer end portion 20Tof the front wall 20F. In some embodiments, in other words, a fragileportion or the like that is easily broken may be provided at the seatwidth direction outer end portion 20T of the front wall 20F.

When the portion to be broken is the seat width direction outer endportion 20T of the front wall 20F, the front wall 20F is opened with aseat width direction inner end portion 20N as a hinge portion, so thatthe airbag body 32 to be deployed can be further suppressed from cominginto contact with the head Ph of the occupant P.

Further, as shown in FIG. 3 , in the housing portion S1 provided in theside portion 24R, a cloth (hereinafter referred to as a “guide cloth”)42 as a guide member 40 that protrudes from the side portion 24R(housing portion S1) prior to deployment of the airbag body 32 and isinterposed between the airbag body 32 and the head Ph of the occupant Pis provided.

One end portion of the guide cloth 42 is fixed by sewing or the like toa side wall 32B on the inner side of a base portion 32A of the airbagbody 32 in the seat width direction, the base portion remaining in thehousing portion S1 even after deployment of the airbag body 32. Theother end portion of the guide cloth 42 is disposed along the innersurface of the outer wall 20A of the side portion 24R by passing througha space between the airbag body 32 housed in a bellows shape and theinner surface of the front wall 20F.

Therefore, as shown in FIG. 4 , when the gas is ejected from theinflator 28 and the airbag body 32 breaks the front wall 20F and isdeployed, the other end portion of the guide cloth 42 is pushed by theairbag body 32 and protrudes from the side portion 24R (housing portionS1), and the guide cloth 42 is interposed between the airbag body 32 andthe head Ph of the occupant P.

In some embodiments, the length of the guide cloth 42 along a protrudingdirection may be a length to the extent that the right side of the faceof the occupant P can be covered in a plan view. Further, in someembodiments, the height of the guide cloth 42 (length along the up-downdirection) may be a height to the extent that the right side of the faceof the occupant P can be covered, and approximately 250 mm to 300 mm,for example.

Further, in some embodiments, the guide cloth 42 may have higherrigidity than the airbag body 32, and a coated cloth in which a material(base cloth) constituting the airbag body 32 is coated with siliconrubber or the like be adopted. However, the guide cloth 42 is notlimited to this, and may be composed of, for example, the same materialas the airbag body 32.

Further, as shown in FIG. 5 , three first non-expanding portions 35extending in the up-down direction are provided to be sewn atpredetermined intervals in the up-down direction. The firstnon-expanding portions 35 are provided at the substantially centralportion of the airbag body 32 in the front-rear direction in a statewhere the airbag body 32 is not filled with the gas. A secondnon-expanding portion 37 extending in the front-rear direction iscontinuously provided to be sewn on the upstream side with respect tothe first non-expanding portion 35 in a deployment direction, the firstnon-expanding portion 35 being located at the substantially centralportion in the up-down direction.

The first non-expanding portions 35 and the second non-expanding portion37 allow the tip chamber 36 to bend inward in the seat width directionwith respect to the front-rear chamber 34, and to be deployed inward inthe seat width direction. That is, in the airbag body 32, the upstreamside with respect to the first non-expanding portions 35 in thedeployment direction is the front-rear chamber 34, and the downstreamside with respect to the first non-expanding portions 35 in thedeployment direction is the tip chamber 36.

Next, the operation of the airbag device 30 according to the firstembodiment having the above configuration will be described.

When the detection device detects that a frontal collision has occurredthe vehicle, the inflator 28 is operated and instantly ejects gas intothe airbag body 32. When the gas is ejected into the airbag body 32, theairbag body 32 is deployed. However, prior to the deployment of theairbag body 32, the guide cloth 42 protrudes from the side portion 24R.That is, the front wall 20F of the side portion 24R is broken by theairbag body 32 to be deployed, and the other end portion of the guidecloth 42 is pushed out from the side portion 24R (housing portion S1).

As a result, the guide cloth 42 is interposed between the airbag body 32and the head Ph of the occupant P, and the airbag body 32 is deployedforward along the side window 18 on the outer side of the guide cloth 42in the seat width direction. That is, the airbag body 32 is deployedforward through the clearance between the side window 18 and the guidecloth 42 (head Ph of the occupant P) from the side portion 24R.

Therefore, at the time of deployment, even when the head Ph of theoccupant P is closer to the side window 18 side, as shown by solid linesin FIGS. 3 and 4 for example, from the position indicated by long dasheddouble-short dashed lines, and the clearance between the side window 18and the guide cloth 42 (head Ph of the occupant P) is narrow, the airbagbody 32 is not likely to get caught on the head Ph of the occupant P andcan be easily and smoothly deployed along the side window 18.

Then, the head Ph and at least a part of the chest of the occupant Pseated on the vehicle seat 10 is restrained by the fully deployed airbagbody 32 (front-rear chamber 34 and tip chamber 36). Therefore, it ispossible to suppress movement of the head Ph and at least the part ofthe chest of the occupant P forward due to the inertial force by theairbag body 32 (front-rear chamber 34 and tip chamber 36).

Further, as described above, the guide cloth 42 protrudes prior to thedeployment of the airbag body 32 and is interposed between the airbagbody 32 and the head Ph of the occupant P. Therefore, when the airbagbody 32 is deployed, there is no possibility that the face of theoccupant P will be hurt by the airbag body 32. In other words, the guidecloth 42 can protect the face of the occupant P.

Further, since the guide member 40 is composed of the guide cloth 42,the head Ph of the occupant P is less likely to be hurt than when theguide member 40 is composed of, for example, a plastic material evenwhen the guide member 40 (guide cloth 42) hits the head Ph of theoccupant P.

Further, when the airbag body 32 is deployed, the front wall 20F isopened with the seat width direction inner end portion 20N as a hingeportion. Therefore, the airbag body 32 to be deployed can be furthersuppressed from coming into contact with the head Ph of the occupant Pby the front wall 20F.

Second Embodiment

Next, the airbag device 30 according to a second embodiment will bedescribed. The same parts as those in the first embodiment aredesignated by the same reference signs, and detailed description thereof(including common operations) will be omitted as appropriate.

As shown in FIG. 6 , the second embodiment differs from the firstembodiment only in that the guide cloth 42 is not provided and the guidemember 40 is composed of only the front wall 20F. That is, the frontwall 20F of which the seat width direction outer end portion 20T isbroken due to the deployment of the airbag body 32 is opened with theseat width direction inner end portion 20N as a hinge portion, so thatthe front wall 20F is interposed between the airbag body 32 to bedeployed and the head Ph of the occupant P.

As a result, when the airbag body 32 is deployed forward through theclearance between the side window 18 and the head Ph of the occupant Pfrom the side portion 24R by the gas ejected from the inflator 28, theairbag body 32 is suppressed or prevented from getting caught on thehead Ph of the occupant P, and can be easily and smoothly deployed alongthe side window 18.

Further, when the guide member 40 is composed of only the front wall 20Fof the side portion 24R as in the second embodiment, the manufacturingcost of the case portion 20 (headrest 16) can be reduced as comparedwith a case where the guide member 40 is provided separately from theside portion 24R (for example, the guide member 40 is composed of onlythe guide cloth 42).

Third Embodiment

Next, the airbag device 30 according to a third embodiment will bedescribed. The same parts as those in the first embodiment and thesecond embodiment are designated by the same reference signs, anddetailed description thereof (including common operations) will beomitted as appropriate.

As shown in FIGS. 7 and 8 , the third embodiment is different from thefirst embodiment and the second embodiment only in that a guide cloth 44is provided at the seat width direction outer end portion 20T of thefront wall 20F. That is, the guide member 40 in the third embodiment iscomposed of the front wall 20F and the guide cloth 44.

The guide cloth 44 is different from the guide cloth 42 only in that thelength of the guide cloth 44 along the protruding direction is shorterthan that of the guide cloth 42, and the height thereof (length alongthe up-down direction) is the same as that of the guide cloth 42. Then,one end portion of the guide cloth 44 is attached to the seat widthdirection outer end portion 20T of the front wall 20F by sewing or thelike, and the other end portion of the guide cloth 44 is disposed alongthe inner surface of the outer wall 20A of the side portion 24R.

In this state, the other end portion of the guide cloth 44 is disposedat the same position as the other end portion of the guide cloth 42. Inother words, the length of the guide cloth 44 along the protrudingdirection is set such that the other end portion of the guide cloth 44disposed along the inner surface of the outer wall 20A of the sideportion 24R is disposed at the same position as the other end portion ofthe guide cloth 42.

With the guide member 40 having such a configuration, as shown in FIG. 8, the seat width direction outer end portion 20T of the front wall 20Fof the side portion 24R is broken by the airbag body 32 to be deployed,and when the front wall 20F pivots with the seat width direction innerend portion 20N as a hinge portion, the other end portion of the guidecloth 44 is pushed out from the side portion 24R (housing portion S1).

As a result, the front wall 20F and the guide cloth 44 are interposedbetween the airbag body 32 and the head Ph of the occupant P, and theairbag body 32 is deployed forward along the side window 18 on the outerside of the front wall 20F and the guide cloth 44 in the seat widthdirection. That is, the airbag body 32 is deployed forward through theclearance between the side window 18, and the front wall 20F and theguide cloth 44 (head Ph of the occupant P) from the side portion 24R.

Therefore, at the time of deployment, even when the head Ph of theoccupant P is closer to the side window 18 side, as shown by solid linesin FIGS. 7 and 8 for example, from the position indicated by long dasheddouble-short dashed lines, and the clearance between the side window 18,and the front wall 20F and the guide cloth 44 (head Ph of the occupantP) is narrow, the airbag body 32 is not likely to get caught on the headPh of the occupant P and can be easily and smoothly deployed along theside window 18.

Further, when the guide member 40 is composed of the front wall 20F ofthe side portion 24R and the guide cloth 44 provided in the front wall20F as in the third embodiment, the manufacturing cost of the caseportion 20 (headrest 16) can be reduced as compared with a case wherethe guide member 40 is composed of only the guide cloth 42.

The seat-mounted airbag device 30 according to the present embodimenthas been described above with reference to the drawings, but theseat-mounted airbag device 30 according to the present embodiment is notlimited to the illustrated embodiments and its design can be changed asappropriate within the scope of the present disclosure. For example, thereaction force plate that supports the inflator 28 may be fixed via abracket to the headrest support 26 instead of the seat back frame.

Further, the guide member 40 is not limited to the guide cloth 42 or thefront wall 20F, and further a member composed of the front wall 20F andthe guide cloth 44. The guide member 40 may have any configuration aslong as the guide member 40 protrudes from the side portion 24R prior tothe deployment of the airbag body 32 and is interposed between theairbag body 32 and the head Ph of the occupant P.

For example, the guide member 40 may slide along the inner surface ofthe inner peripheral wall 20C of the case portion 20 and protrude withthe deployment of the airbag body 32, and may be composed of asheet-shaped member that is made of soft resin and is interposed betweenthe airbag body 32 and the head Ph of the occupant P.

What is claimed is:
 1. A seat-mounted airbag device comprising: aninflator that is operated when a vehicle collision is detected orpredicted and ejects gas; an airbag body that includes a front-rearchamber configured to be deployed forward of a seat through a clearancebetween a window and a head of an occupant from a side portion of aheadrest on a window side by the gas ejected from the inflator andconfigured to be disposed between the window and the head of theoccupant, and a tip chamber that is deployed inward in a seat widthdirection from an end portion of the front-rear chamber on a seat frontside and configured to be disposed forward of a face of the occupant onthe seat front side, the airbag body bent in a V-shape in a plan viewwhen deployed, and; and a guide member that protrudes from the sideportion prior to deployment of the airbag body and is configured to beinterposed between the airbag body and the head of the occupant.
 2. Theseat-mounted airbag device according to claim 1, wherein the guidemember is composed of a cloth.
 3. The seat-mounted airbag deviceaccording to claim 1, wherein the guide member is composed of a frontwall of the side portion.
 4. The seat-mounted airbag device according toclaim 1, wherein the guide member is composed of a front wall of theside portion and a cloth provided at the front wall.